Noteworthy Thursday Option Activity: C, ZS, WING

Looking at options trading activity among components of the Russell 3000 index, there is noteworthy activity today in Citigroup Inc (Symbol: C), where a total volume of 143,795 contracts has been traded thus far today, a contract volume which is representative of approximately 14.4 million underlying shares (given that every 1 contract represents 100 underlying shares). That number works out to 67.2% of C's average daily trading volume over the past month, of 21.4 million shares. Especially high volume was seen for the $57.50 strike call option expiring February 15, 2019 , with 18,587 contracts trading so far today, representing approximately 1.9 million underlying shares of C. Below is a chart showing C's trailing twelve month trading history, with the $57.50 strike highlighted in orange:

Zscaler Inc (Symbol: ZS) saw options trading volume of 8,772 contracts, representing approximately 877,200 underlying shares or approximately 66.2% of ZS's average daily trading volume over the past month, of 1.3 million shares. Especially high volume was seen for the $49 strike call option expiring February 15, 2019 , with 1,544 contracts trading so far today, representing approximately 154,400 underlying shares of ZS. Below is a chart showing ZS's trailing twelve month trading history, with the $49 strike highlighted in orange:

And Wingstop Inc (Symbol: WING) saw options trading volume of 4,188 contracts, representing approximately 418,800 underlying shares or approximately 61.6% of WING's average daily trading volume over the past month, of 679,385 shares. Especially high volume was seen for the $76.95 strike call option expiring February 15, 2019 , with 2,575 contracts trading so far today, representing approximately 257,500 underlying shares of WING. Below is a chart showing WING's trailing twelve month trading history, with the $76.95 strike highlighted in orange: